Suzuki-Miyaura C-C Coupling Reactions Catalyzed by Supported Pd Nanoparticles for the Preparation of Fluorinated Biphenyl Derivatives

Heterogeneous recyclable catalysts in Suzuki-Miyaura C-C coupling reactions are of great interest in green chemistry as reusable alternatives to homogeneous Pd complexes. Considering the interesting properties of fluorinated compounds for the pharmaceutical industry, as precursors of novel materials, and also as components of liquid crystalline media, this present study describes the preparation of different fluorinated biphenyl derivatives by Suzuki-Miyaura coupling reactions catalyzed by a heterogeneous system (G-COOH-Pd-10) based on Pd nanoparticles supported onto COOH-modified graphene. The catalytic activity of the hybrid material G-COOH-Pd-10 has been tested in Suzuki-Miyaura C–C coupling reactions observing excellent versatility and good conversion rates in the reactions of phenylboronic acid, 4-vinylphenylboronic acid, 4-carboxyphenylboronic acid, and 4-fluorophenylboronic acid with 1-bromo-4-fluorobenzene. In addition, the influence of the arylbromide has been studied by carrying out reactions of 4-fluorophenylboronic acid with 1-bromo-2-fluorobenzene, 1-bromo-3-fluorobenzene, 1-bromo-4-fluorobenzene, 2-bromo-5-fluorotoluene, and 2-bromo-4-fluorotoluene. Finally, catalyst recyclability tests show a good degree of reusability of the system based on G-COOH-Pd-10 as the decrease in catalytic activity after five consecutive catalytic cycles in the reaction of 1-bromo-4-fluorobenzene with 4-florophenylboronic acid at 48 hours of reaction is lower than 8% while in the case of reactions at three hours the recyclability of the systems is much lower.We gratefully acknowledge financial support from the Ministerio de Economía y Competitividad, Spain (Grant no. CTQ2015-66164-R). We would also like to thank Universidad Rey Juan Carlos and Banco de Santander for supporting our Research Group of Excellence QUINANOAP. We would also like to thank Isfahan University of Technology for the partial financial support of the research stay of R.S.E

Applications of Nanomaterials Based on Magnetite and Mesoporous Silica on the Selective Detection of Zinc Ion in Live Cell Imaging

Functionalized magnetite nanoparticles (FMNPs) and functionalized mesoporous silica nanoparticles (FMSNs) were synthesized by the conjugation of magnetite and mesoporous silica with the small and fluorogenic benzothiazole ligand, that is, 2(2-hydroxyphenyl)benzothiazole (hpbtz). The synthesized fluorescent nanoparticles were characterized by FTIR, XRD, XRF, 13C CP MAS NMR, BET, and TEM. The photophysical behavior of FMNPs and FMSNs in ethanol was studied using fluorescence spectroscopy. The modification of magnetite and silica scaffolds with the highly fluorescent benzothiazole ligand enabled the nanoparticles to be used as selective and sensitive optical probes for zinc ion detection. Moreover, the presence of hpbtz in FMNPs and FMSNs induced efficient cell viability and zinc ion uptake, with desirable signaling in the normal human kidney epithelial (Hek293) cell line. The significant viability of FMNPs and FMSNs (80% and 92%, respectively) indicates a potential applicability of these nanoparticles as in vitro imaging agents. The calculated limit of detections (LODs) were found to be 2.53 X 10-6 and 2.55 X 10-6 M for Fe3O4-H@hpbtz and MSN-Et3N-IPTMS-hpbtz-f1, respectively. FMSNs showed more pronounced zinc signaling relative to FMNPs, as a result of the more efficient penetration into the cells.This research was funded by several sources. The URJC authors thank the financial support of theMinisterio de Economía y Competitividad and FEDER (Grants nos. CTQ2015-66164-R and CTQ2017-90802-REDT) and Universidad Rey Juan Carlos-Banco de Santander for supporting our excellence group QUINANOAP. The partial support of this work by the Isfahan University of Technology Research Council (grant number 500/95/24305 and the Iran National Science Foundation through INSF grant number 95828071 is also acknowledged. The CNIC is supported by the Spanish Ministerio de Ciencia, Innovación y Universidades and the Pro-CNIC Foundation and is a Severo Ochoa Center of Excellence (SEV-2015-0505). M.F. would like to thank MEyC for the research grant no. SAF2014-59118-JIN, co-funded by Fondo Europeo de Desarrollo Regional (FEDER) and COST Action CA1520: ‘European Network on NMR Relaxometry-EURELAX’. M.F. would also like to thank the Community of Madrid for research contract num. 2017-T1/BIO-4992 (‘Atraccion de Talento’ Action) cofunded by Universidad Complutense de Madrid

Electrolysis of low-grade and saline surface water

Review Article Published: 17 February 2020 Electrolysis of low-grade and saline surface water Wenming Tong, Mark Forster, Fabio Dionigi, Sören Dresp, Roghayeh Sadeghi Erami, Peter Strasser, Alexander J. Cowan & Pau Farràs Nature Energy (2020)Cite this article 1779 Accesses 1 Citations 60 Altmetric Metricsdetails Abstract Powered by renewable energy sources such as solar, marine, geothermal and wind, generation of storable hydrogen fuel through water electrolysis provides a promising path towards energy sustainability. However, state-of-the-art electrolysis requires support from associated processes such as desalination of water sources, further purification of desalinated water, and transportation of water, which often contribute financial and energy costs. One strategy to avoid these operations is to develop electrolysers that are capable of operating with impure water feeds directly. Here we review recent developments in electrode materials/catalysts for water electrolysis using low-grade and saline water, a significantly more abundant resource worldwide compared to potable water. We address the associated challenges in design of electrolysers, and discuss future potential approaches that may yield highly active and selective materials for water electrolysis in the presence of common impurities such as metal ions, chloride and bio-organisms.W.T., M.F., R.S.E., A.J.C. and P.F. acknowledge financial support from INTERREG Atlantic Area programme (Grant reference EAPA_190_2016). P.F. acknowledges support from Royal Society Alumni programme. F.D., S.D. and P.S. gratefully acknowledge financial support by the German Research Foundation (DFG) through Grant reference number STR 596/8-1 and the federal ministry for economic affairs and energy (Bundesministerium für Wirtschaft und Energie, BMWi) under grant number 03EIV041F. P.S. acknowledges partial funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany´s Excellence Strategy – EXC 2008/1 – 390540038 (zum Teil gefördert durch die Deutsche Forschungsgemeinschaft (DFG) im Rahmen der Exzellenzstrategie des Bundes und der Länder – EXC 2008/1 – 390540038).peer-reviewed2020-08-1

Inhibitive effect of sodium (E)-4-(4-nitrobenzylidenamino) benzoate on the corrosion of some metals in sodium chloride solution

The inhibition performance of a novel anionic carboxylic Schiff base, sodium (E)-4-(4-nitrobenzylideneamino)benzoate (SNBB), was investigated for various metals, namely low carbon steel F111, pure iron and copper, in neutral 10 mM NaCl solution. Potentiodynamic polarization, scanning vibrating electrode technique (SVET), quantum chemical (QC) calculation, and molecular dynamics (MD) simulation were employed. The potentiodynamic polarization data showed that SNBB acts as an effective corrosion inhibitor for both iron and F111 steel, but it is not effective for the copper. In situ spatially-resolved SVET maps evidenced a major change in surface reactivity for Fe and F111 steel immersed in 10 mM aqueous solution in the absence and in the presence of SNBB. Featureless ionic current density distributions were recorded in the presence of SNBB at both their spontaneous open circuit potential (OCP) and under mild anodic polarization conditions, while major ionic flows were monitored above the metals in the absence of SNBB. On the basis of computer simulations, it is proposed that SNBB produces a stable chelate film on iron and steel surfaces that accounts for the good corrosion inhibition efficiency observed. The different inhibition efficiencies of SNBB molecules on the iron and copper was attributed to the special chemical structure of SNBB molecule and its different chelation ability with the released metal ions on the metal surface. The QC calculations also confirmed the high corrosion inhibition efficiency of SNBB. The MD simulation indicated higher binding energy of SNBB on iron surface compared to that of copper surface. The interaction mode of SNBB on iron and F111 steel surfaces corresponds to a mixed chemical and physical adsorption, and it obeys the Langmuir isother

Syntheses, characterizations, X-ray crystal structures, and antibacterial activities of Co( II), Ni( II), and Zn( II) complexes of the Schiff base derived from 5-nitro-2hydroxybenzaldehyde and benzylamine

Three new complexes, [(CoL2)-L-II(bzln)(2)] (1), [(NiL2)-L-II(DMF)(2)] (2), and [(ZnL2)-L-II] (3), with the bidentate (NO) Schiff base HL=2-((E)-(benzylimino)methyl)-4-nitrophenol have been synthesized and characterized. [(CoL2)-L-II(bzln)(2)] (1) was initially formed from the reaction of H2L1 (N,N-bis(5-nitrobenzaldehyde)-2-aminobenzylamine=H2L1), with Co-II(CH3COO)(2)4H(2)O in the presence of benzylamine. The X-ray crystal structure of 1 revealed that HL was formed from the hydrolysis of H2L1 and the recondensation of benzylamine with 2-hydroxy-5-nitrobenzaldehyde produced in H2L1 hydrolysis. The Schiff base HL was then prepared by direct reaction of 2-hydroxy-5-nitrobenzaldehyde and benzylamine. Complexes 1-3 were also directly synthesized and their crystal and molecular structures determined by X-ray crystallography. The ligand and its metal complexes were also screened for in vitro antibacterial activity